Adrenal steroids are known to induce hypertension by mineralocorticoid action (aldosterone, deoxycorticosterone) or by anti- diuretic action (18- hydroxydeoxycorticosterone). An investigation is proposed of the mechanisms by which Angiotensin and ACTH regulate the synthesis of these steroids and glucocorticoids in the adrenal cortex. Methods will be developed to separate and characterize several forms of mitochondrial cytochrome P450 which function in specific steroidogenic hydroxylations and which are regulated by the hormones. Particular emphasis will be placed on the regulation of cholesterol side chain cleavage. The role of protein synthesis in the activation of steroidogenesis by ACTH and Angiotensin II will be critically examined and correlated with the regulation of intracellular cholesterol transport to the appropriate cytochrome P450. This project aims at a biochemical understanding of changes in the relative plasma levels of adrenal steroids which is an important consideration in the control of blood pressure.